JP3865601B2 - Electromagnetic wave suppression sheet - Google Patents

Electromagnetic wave suppression sheet Download PDF

Info

Publication number
JP3865601B2
JP3865601B2 JP2001177510A JP2001177510A JP3865601B2 JP 3865601 B2 JP3865601 B2 JP 3865601B2 JP 2001177510 A JP2001177510 A JP 2001177510A JP 2001177510 A JP2001177510 A JP 2001177510A JP 3865601 B2 JP3865601 B2 JP 3865601B2
Authority
JP
Japan
Prior art keywords
electromagnetic wave
sheet
magnetic particles
rubber
powder
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
JP2001177510A
Other languages
Japanese (ja)
Other versions
JP2002368480A (en
Inventor
一雅 五十嵐
準一 豊田
克巳 岡山
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nitto Denko Corp
Sony Corp
Original Assignee
Nitto Denko Corp
Sony Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nitto Denko Corp, Sony Corp filed Critical Nitto Denko Corp
Priority to JP2001177510A priority Critical patent/JP3865601B2/en
Priority to US10/166,024 priority patent/US6695985B2/en
Priority to EP02013406.0A priority patent/EP1267406B1/en
Publication of JP2002368480A publication Critical patent/JP2002368480A/en
Application granted granted Critical
Publication of JP3865601B2 publication Critical patent/JP3865601B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00Details of semiconductor or other solid state devices
    • H01L23/552Protection against radiation, e.g. light or electromagnetic waves
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42Wire connectors; Manufacturing methods related thereto
    • H01L2224/44Structure, shape, material or disposition of the wire connectors prior to the connecting process
    • H01L2224/45Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
    • H01L2224/45001Core members of the connector
    • H01L2224/45099Material
    • H01L2224/451Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof
    • H01L2224/45138Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof the principal constituent melting at a temperature of greater than or equal to 950°C and less than 1550°C
    • H01L2224/45144Gold (Au) as principal constituent
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42Wire connectors; Manufacturing methods related thereto
    • H01L2224/47Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/4805Shape
    • H01L2224/4809Loop shape
    • H01L2224/48091Arched
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42Wire connectors; Manufacturing methods related thereto
    • H01L2224/47Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/481Disposition
    • H01L2224/48151Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/48221Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/48245Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic
    • H01L2224/48247Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic connecting the wire to a bond pad of the item
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L24/00Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L24/42Wire connectors; Manufacturing methods related thereto
    • H01L24/44Structure, shape, material or disposition of the wire connectors prior to the connecting process
    • H01L24/45Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L24/00Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L24/42Wire connectors; Manufacturing methods related thereto
    • H01L24/47Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L24/48Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/0001Technical content checked by a classifier
    • H01L2924/00014Technical content checked by a classifier the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/01Chemical elements
    • H01L2924/01012Magnesium [Mg]
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/01Chemical elements
    • H01L2924/01019Potassium [K]
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/01Chemical elements
    • H01L2924/0102Calcium [Ca]
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/01Chemical elements
    • H01L2924/01025Manganese [Mn]
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/01Chemical elements
    • H01L2924/01079Gold [Au]
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/10Details of semiconductor or other solid state devices to be connected
    • H01L2924/11Device type
    • H01L2924/12Passive devices, e.g. 2 terminal devices
    • H01L2924/1204Optical Diode
    • H01L2924/12042LASER
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/15Details of package parts other than the semiconductor or other solid state devices to be connected
    • H01L2924/181Encapsulation
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/30Technical effects
    • H01L2924/301Electrical effects
    • H01L2924/3025Electromagnetic shielding
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/32Composite [nonstructural laminate] of inorganic material having metal-compound-containing layer and having defined magnetic layer

Description

【0001】
【発明の属する技術分野】
本発明は、充分な電気絶縁性と電磁波抑制機能とを備えた電磁波抑制体シートに関するものである。
【0002】
【従来の技術】
一般に、電気機器では電磁環境両立性(EMC:Electro-magnetic Compatibility)の問題が顕在化しており、不要電磁波の放出と耐性の両面からの対策がなされている。近年、情報通信機器は小型高機能化が進み、高性能化のために半導体素子の動作周波数が一段と上昇する傾向にあり、特に、デジタル信号の高速化では消費電力の低減のために信号の振幅値が低下しており、微弱な高周波ノイズでも誤動作する危険性が高まっている。
【0003】
このようなことから、従来、その対策の一つとして、半導体パッケージを金属キャップで覆ったり、またはプリント配線回路基板にフィルタを実装したりすることが行われてきたが、余分な実装空間を必要とする等の理由により電子部品の実装密度が充分に上がらず他の解決方法が検討されている。現在では、このような背景から高密度実装に適した電磁波遮蔽技術が求められており、例えば、特開平9−35927号公報(以下「従来技術」という)にて提案されているように、電子機器の不要電磁波を吸収してシールドする方法の一つとして、複素透磁率の虚数部分であるμ″(以下「虚数部透磁率」という)が大きい軟磁性体粒子を合成樹脂中に分散配合してなる電磁波抑制体シートを電子機器の不要電磁波発生箇所近傍に設置することが知られている。
【0004】
【発明が解決しようとする課題】
上記電磁波抑制体シート中に分散・配合してなる従来用いられてきた磁性粒子の中には、その絶縁抵抗値の小さいものが存在する。しかしながら、上記絶縁抵抗値の小さな磁性粒子を高充填して分散・配合した材料を用いて製造してなる電磁波抑制体シートを、直接、半導体パッケージのリードピン上に設置したり、またはプリント配線回路基板の導体上に設置した場合、短絡するという危険性があった。または、短絡に至らないまでも、電磁波抑制体シートの電気絶縁抵抗値が小さくなるため、電気信号が他の信号線路に流れ込む、いわゆる信号のクロストークの危険性もあった。
【0005】
このようなことから、電気絶縁性の確保のために、前記従来技術においては、使用する軟磁性体粒子に対して気相徐酸法または液相徐酸法といった酸化法を用いて軟磁性体粒子表面に酸化膜を形成することにより、非良導性にする技術が開示されている。しかしながら、前記従来技術で得られる電磁波抑制体シートの表面抵抗値は107 〜108 Ωであり、不要輻射の低減に効果はあっても、上記電磁波抑制体シートを半導体パッケージのリードピン上に設置した場合、短絡やクロストークの対策としては不充分といわざるを得なかった。
【0006】
上記のような観点から、電磁波抑制体シートに高充填する磁性粒子としては虚数部透磁率μ″が大きいとともに、電気絶縁性をも兼ね備えたものが求められている。
【0007】
本発明は、このような事情に鑑みなされたものであって、電子機器からの不要輻射電磁波を高度に低減可能で、虚数部透磁率μ″が大きいとともに優れた電気絶縁性を兼ね備えた電磁波抑制体シートの提供をその目的とする。
【0008】
【課題を解決するための手段】
上記の目的を達成するため、本発明の電磁波抑制体シートは、最大粒径が500μm以下で、平均粒子径が1〜100μmの範囲の磁性粒子表面が、一次粒子の平均粒子径が10〜100nmであるシリカ微粉末によって、機械的衝撃力を利用して被覆処理された複合化磁性粒子の粉体が分散されている合成樹脂またはゴムからなる材料によってシート状に形成されてなるという構成をとる。
【0009】
すなわち、本発明者らは、電磁障害対策として、磁性粒子の磁気損失を利用した不要輻射低減特性に優れた電磁波抑制体シートを得るために、その充填剤として用いられる磁性粒子の電気絶縁性を中心に一連の研究を重ねた。その結果、特定の粒径の磁性粒子の表面を、機械的衝撃力を利用して特定の粒径のシリカ微粉末で被覆処理してなる複合化磁性粒子を用いると、体積抵抗率が充分に高く、しかも電気絶縁性が著しく向上した電磁波抑制体シートが得られることを見出し本発明に到達した。
【0010】
【発明の実施の形態】
つぎに、本発明の実施の形態について詳しく説明する。
【0011】
本発明の電磁波抑制体シートは、特殊な複合化磁性粒子を分散・配合してなる合成樹脂またはゴムからなる材料を用いてシート状に成形してなるものである。
【0012】
上記シートを形成する合成樹脂またはゴムとしては、シート状に成形可能なものであれば特に限定するものではなく従来公知のもの、例えば、ポリエチレン樹脂、塩素化ポリエチレン樹脂等のポリオレフィン系樹脂、ポリエステル樹脂、ポリ塩化ビニル樹脂、シリコーン樹脂、ポリ(メタ)アクリレート樹脂、ポリウレタン樹脂、ポリアミド樹脂、天然ゴム、イソプレンゴム、ブタジエンゴム、アクリロニトリル−ブタジエンゴム、カルボキシル化ニトリルゴム、エチレン−アクリルゴム、エチレン−プロピレンゴム、エチレン−プロピレン−ジエンゴム、エチレン−酢酸ビニルゴム、ポリエーテルウレタンゴム、アクリロニトリル−ブタジエン−スチレンゴム、スチレン−ブタジエンゴム、アクリルゴム、フッ素ゴム、フッ化シリコーンゴム、フッ化ビニリデンゴム、四フッ化エチレン−プロピレンゴム、四フッ化エチレン−パーフルオロメチルビニルエーテルゴム等の、フォスファゼン系フッ素ゴム等の熱可塑性樹脂、エポキシ樹脂、フェノール樹脂、熱硬化ポリウレタン樹脂、熱硬化不飽和ポリエステル樹脂、メラミン樹脂等の熱硬化性樹脂、ポリイミド樹脂、芳香族ポリアミド樹脂等の耐熱性樹脂等があげられる。
【0013】
上記特殊な複合化磁性粒子は、表面が絶縁性無機材料によって被覆処理された磁性粒子である。
【0014】
上記絶縁性無機材料による処理対象となる磁性粒子としては、ヘマタイト(Fe2 3 )、マグネタイト(Fe3 4 )、さらに一般式:MFe2 4 や、MO・nFe2 3 (両式中、Mは2価の金属粒子であり、Mn,Co,Ni,Cu,Zn,Ba,Mg等があげられる。また、nは正数である。そして、Mは繰り返し時において同種であってもよく異種であってもよい)で表される各種フェライト、ケイ素鋼粉、パーマロイ(Fe−Ni合金)、Co基アモルファス合金、センダスト(Fe−Al−Si合金)、アルパーム、スーパーマロイ、ミューメタル、パーメンター、パーミンバー等の各種金属粉やその合金粉、磁性粉等が用いられる。これらは単独でもしくは2種以上併せて用いられる。
【0015】
上記磁性粒子としては、最大粒径が500μm以下で、平均粒子径が1〜100μmの範囲のものを用いる必要がある。特に好ましくは平均粒子径が10〜50μmの範囲である。上記最大粒子径および平均粒子径は、例えば、レーザー回析散乱式粒度分布測定装置を用いて測定することができる。
【0016】
本発明において、処理対象となる上記磁性粒子の形状としては、鱗片状(フレーク状)、偏平状、樹枝状、角状、粒状、針状、海綿状および球状からなる群から選ばれた少なくとも一つの形状を有するものが好ましい。特に、鱗片状(フレーク状)、偏平状等のアスペクト比の大きな形状を有するものが好適である。すなわち、アスペクト比が大きな偏平状であるほど、磁界異方性が大きくなり、結果として、表面処理された複合化磁性粒子を分散・配合してなる電磁波抑制体シートとしての磁気損失を大きくすることができ、不要輻射の低減効果が大きくなる。
【0017】
上記磁性粒子の表面処理に用いられる絶縁性無機材料としては、シリカ微粉末が用いられ、なかでも球状シリカ微粉末、摩砕処理シリカ微粉末、破砕状シリカ微粉末等が好ましい。そして、粒子径が微細であるという観点から、一次粒子の平均粒子径が10〜100nmの上記シリカ微粉末が用いられる。
【0018】
上記表面がシリカ微粉末によって被覆処理された磁性粒子である特殊な複合化磁性粒子は、つぎのようにして製造することができる。すなわち、磁性粒子とシリカ微粉末を高速回転するローター,ステーターおよび循環回路を有する表面処理装置に投入し、圧縮,摩擦,剪断等の機械的衝撃力を利用した機械的作用を繰り返して受ける処理法等の従来公知の複合化方法を用いることにより上記特殊な複合化磁性粒子を製造することができる。このような処理により、上記磁性粒子の表面にシリカ微粉末がまぶされて、いわゆるシリカ微粉末によってその表面が被覆された状態の複合化磁性粒子が得られる。
【0019】
このように、虚数部透磁率μ″が大きいとともに、電気絶縁性をも兼ね備えた磁性粒子を用いて得られる複合化磁性粒子を、分散・配合してなる電磁波抑制体シートにおいて、上記特殊な複合化磁性粒子の含有量は、電磁波抑制体シート形成材料全体中の30〜95重量%となるよう設定することが好ましい。より好ましくは50〜90重量%であり、特に好ましくは70〜85重量%である。すなわち、特殊な複合化磁性粒子の含有量が95重量%を超えると、後述するシートの製造が困難となり、またボイド等の欠陥が生じ易くなる。また、30重量%未満では電磁波抑制体シートとしての磁気損失の効果が不充分となる傾向がみられるからである。
【0020】
さらに、上記特殊な複合化磁性粒子は、主成分である合成樹脂またはゴムとの濡れ性を向上させるために各種公知のカップリング剤で表面処理してもよい。
【0021】
上記カップリング剤としては、磁性粒子の表面に存在するシリカ微粉末を処理できるものであれば特に限定するものではなく従来公知のもの、例えば、γ−グリシドキシプロピルトリメトキシシラン、β−(3,4−エポキシシクロヘキシル)エチルトリメトキシシラン等のシランカップリング剤、チタネート系カップリング剤、アルミニウムキレートカップリング剤等があげられる。
【0022】
本発明の電磁波抑制体シートの形成材料には、上記合成樹脂またはゴムおよび特殊な複合化磁性粒子以外に必要に応じて他の添加剤を適宜配合してよい。
【0023】
上記添加剤としては、熱伝導性無機質充填剤、低応力化剤、着色剤、カップリング剤および難燃剤等があげられる。
【0024】
上記熱伝導性無機質充填剤としては、アルミナ粉末、窒化アルミニウム粉末、窒化珪素粉末、窒化硼素粉末、コバール粉末等があげられる。
【0025】
上記低応力化剤としては、側鎖エチレングリコールタイプジメチルシロキサン等のシリコーン化合物、アクリロニトリル−ブタジエンゴム等があげられる。
【0026】
上記着色剤としては、カーボンブラック、酸化チタン等の顔料や各種染料があげられる。また、上記離型剤としては、ポリエチレンワックス、カルナバワックス、脂肪酸塩等があげられる。
【0027】
また、上記カップリング剤としては、先に述べたと同様のもの、例えば、γ−グリシドキシプロピルトリメトキシシラン、β−(3,4−エポキシシクロヘキシル)エチルトリメトキシシラン等のシランカップリング剤等があげられる。
【0028】
上記難燃剤としては、臭素化難燃剤、リン含有難燃剤、水酸化アルミニウム、水酸化マグネシウム等があげられる。
【0029】
さらに、上記難燃剤以外に、下記の一般式(1)で表される多面体形状の複合化金属水酸化物を用いることができる。この複合化金属水酸化物は、結晶形状が多面体形状を有するものであり、従来の六角板形状を有するもの、あるいは、鱗片状等のように、いわゆる厚みの薄い平板形状の結晶形状を有するものではなく、縦、横とともに厚み方向(c軸方向)への結晶成長が大きい、例えば、板状結晶のものが厚み方向(c軸方向)に結晶成長してより立体的かつ球状に近似させた粒状の結晶形状、例えば、略12面体、略8面体、略4面体等の形状を有する金属水酸化物をいう。
【0030】
【化1】

Figure 0003865601
【0031】
このような結晶形状が多面体形状を有する金属水酸化物は、例えば、金属水酸化物の製造工程における各種条件等を制御することにより、縦,横とともに厚み方向(c軸方向)への結晶成長が大きい、所望の多面体形状、例えば、略12面体、略8面体、略4面体等の形状を有する金属水酸化物を得ることができ、通常、これらの混合物からなる。
【0032】
上記多面体形状を有する金属水酸化物の具体的な代表例としては、Mg1-X NiX (OH)2 〔0.01<X<0.5〕、Mg1-X ZnX (OH)2 〔0.01<X<0.5〕等があげられる。これら金属水酸化物の市販品としては、例えば、タテホ化学工業社製のエコーマグをあげることができる。
【0033】
また、上記多面体形状を有する金属水酸化物のアスペクト比は、通常1〜8、好ましくは1〜7、特に好ましくは1〜4である。ここでいうアスペクト比とは、金属水酸化物の長径と短径との比で表したものである。すなわち、アスペクト比が8を超えると、この金属水酸化物を含有するエポキシ樹脂組成物が溶融したときの粘度低下に対する効果が乏しくなる。
【0034】
本発明の電磁波抑制体シートは、例えば、つぎのようにして製造することができる。すなわち、必須成分である合成樹脂またはゴムおよび複合化磁性粒子、その他の添加剤を所定量配合し、熱ロールやエクストルーダー、ニーダー等を用い充分に溶融分散により混合して圧延ロールを通すことによりシート状に成形する。または、一度冷却した後、熱プレス成形機等により圧縮成形してシート状に成形する。あるいは、合成樹脂またはゴムを有機溶剤に溶解したものに、複合化磁性粒子、その他の添加剤を所定量配合し、ホモミキサー等の剪断力の大きな分散機を用いて充分攪拌混合した溶液を、塗工法により剥離基材上に塗布した後乾燥してシートを形成する。このようにして電磁波抑制体シートを製造することができる。
【0035】
このようにして得られる電磁波抑制体シートは、その体積抵抗率が1×1010Ω・cm以上であることが好ましく、特に好ましくは1×1010〜1×1017Ω・cmである。
【0036】
さらに、電磁波抑制体シートの厚みは、使用対象となる部品および用途等により適宜に設定されるが、通常、0.01〜5mm程度に設定される。
【0037】
このようにして得られた電磁波抑制体シートは、例えば、半導体装置等の電子機器全面を覆うように設置して使用される。このような電子機器全面を覆うように設置する等の使用の用途の際には、市販の両面粘着テープ(例えば、日東電工社製のNo.500等)を用いて密着固定する。
【0038】
つぎに、実施例について比較例と併せて説明する。
【0039】
【実施例1】
〔複合化磁性粒子aの準備〕
平均粒子径12μmのMn−Zn系偏平ソフトフェライト粉末と一次粒子径が約12nmの球状シリカ微粉末を準備した。そして、上記Mn−Zn系偏平ソフトフェライト粉末100重量部(以下「部」と略す)に対して上記球状シリカ微粉末が10部となるように用い、高速回転するローター、ステーターおよび循環回路を有する表面処理装置に投入し、回転数4800rpmで3分間運転した後、この装置から排出することによりMn−Zn系偏平ソフトフェライト粉末の表面を上記球状シリカ微粉末で絶縁被覆してなる複合化磁性粒子aを作製した。
【0040】
〔電磁波抑制体シートAの準備〕
つぎに、上記複合化磁性粒子a80部、加硫前ムーニー粘度(100℃)29のシリコーンゴムとエチレン−プロピレン−ジエンモノマー共重合ゴム(EPDM)複合体樹脂20部、γ−グリシドキシプロピルトリメトキシシラン0.8部を秤量して配合し、ジクミルパーオキサイド0.3部を加えながら熱2本ロールを用いて混練・分散した後、圧延ロールを通した。その後、150℃で2時間加硫することにより目的とする電磁波抑制体シートAを作製した。
【0041】
【実施例2】
〔複合化磁性粒子bの準備〕
平均粒子径23μmのNi−Cu−Zn系粒状ソフトフェライト粉末と一次粒子径が約100nmの球状シリカ微粉末を準備した。そして、上記Ni−Cu−Zn系粒状ソフトフェライト粉末100部に対して上記球状シリカ微粉末が10部となるように用い、高速回転するローター、インナーピースを有する表面処理装置に投入し、回転数2600rpmで10分間運転した後、この装置から排出することによりNi−Cu−Zn系偏平ソフトフェライト粉末の表面を上記球状シリカ微粉末で絶縁被覆してなる複合化磁性粒子bを作製した。
【0042】
〔電磁波抑制体シートBの準備〕
上記複合化磁性粒子bを用いた。それ以外は実施例1と同様にして目的とする電磁波抑制体シートBを作製した。
【0043】
【実施例3】
〔電磁波抑制体シートC〕
実施例1で用いたEPDM複合体樹脂を150部用いた。それ以外は実施例1と同様にして目的とする電磁波抑制体シートCを作製した。
【0044】
【実施例4】
〔電磁波抑制体シートD〕
実施例1で用いたEPDM複合体樹脂を10部用いた。それ以外は実施例1と同様にして目的とする電磁波抑制体シートDを作製した。
【0045】
【比較例】
〔磁性粒子eの準備〕
平均粒子径12μmのMn−Zn系偏平ソフトフェライト粉末をそのまま用いた。
【0046】
〔電磁波抑制体シートEの準備〕
つぎに、上記磁性粒子eを73部、γ−グリシドキシプロピルトリメトキシシラン0.73部を用いた。それ以外は実施例1と同様にして目的とする電磁波抑制体シートEを作製した。
【0047】
このようにして得られた各電磁波抑制体シートを用いて、虚数部透磁率μ″、体積抵抗率およびノイズ放射レベルを下記の方法に従って測定・評価した。その結果を後記の表1〜2に併せて示す。
【0048】
〔虚数部透磁率μ″〕
各電磁波抑制体シートを用いて、外径7mm×内径3mm×厚み2mmの円筒ドーナツ状の成形物(同軸管試験用成形物)を作製した。得られた試験片(成形物)を材料定数測定用装置を用いて、ネットワークアナライザーによって周波数900MHzでの複素透磁率μ″を測定した。
【0049】
〔体積抵抗率〕
各電磁波抑制体シートを用いて、厚み3mm×直径50mmの円盤状成形体を作製した。そして、銀ペーストを用いて主電極の直径30mm、ガード電極の直径32mm、対抗電極の直径45mmの銀電極を作製した後、直流500Vを印加して体積抵抗率を測定した(JIS K 6911に準じる)。
【0050】
〔半導体装置を用いたノイズ放射レベル〕
図1に示すように、シリカ粉末含有のエポキシ樹脂系封止材料(日東電工社製、MP−10)からなる封止樹脂層2により半導体素子1(CMOS:1.23×1.18mm、半導体素子1とリードフレーム3とは金ワイヤー4で電気的に接続されている)が封止された半導体装置であるSOP(small out-line package)パッケージのリードピン5を含む全面に、各電磁波抑制体シート(厚み1mm)6を両面粘着テープ(日東電工社製、No.500)を用いて密着設置した。この樹脂封止タイプの半導体パッケージを20MHzで動作させながら、このパッケージの上部6mm上を電磁波探査プローブを用いて、5mmピッチでスキャンしながらパッケージから放射されるノイズ(200〜300MHz間)を測定した。
【0051】
【表1】
Figure 0003865601
【0052】
【表2】
Figure 0003865601
【0053】
上記表1〜表2の結果から、実施例品の電磁波抑制特性に関して虚数部透磁率μ″の値およびSOP半導体パッケージでのノイズ放射レベルは、実施例および比較例とも大差はなく同程度のレベルであるものの、実施例品は体積抵抗率が大きく、電気絶縁抵抗に優れていることがわかる。このことから、実施例品は電気絶縁性に関する改善効果は明らかである。
【0054】
【発明の効果】
以上のように、本発明の電磁波抑制体シートは、最大粒径が500μm以下で、平均粒子径が1〜100μmの範囲の磁性粒子表面が、一次粒子の平均粒子径が10〜100nmであるシリカ微粉末によって、機械的衝撃力を利用して被覆処理された複合化磁性粒子の粉体が分散された合成樹脂またはゴムからなる材料を用いて形成されたものである。このため、電気絶縁性に優れており、半導体パッケージのリードにわたって装着した場合、リード間の短絡あるいはクロストーク等の問題が生じることもなく、効率良く不要輻射を低減できるシートである。また、電子機器に装着する場合、電磁波抑制体シートの裏面には両面粘着テープ等の粘着剤層を形成して電子機器に装着するのが一般的であるが、シートが万一、脱離した時のため、シートは高い絶縁抵抗をもった絶縁体であることが必要である。従来のシート(例えば、鉄−珪素系偏平磁性粒子/ゴム複合シート)では、表面抵抗が106 Ω程度であり、充分な絶縁性を有してなかった。しかし、本発明の電磁波抑制体シートでは、上記特定の粒径のシリカ微粉末で表面被覆された複合化磁性粒子を用いるため、絶縁抵抗が充分に高く、万が一、脱離した時の電子機器の不良を生じない。
【0055】
このようなことから、本発明の電磁波抑制体シートは、磁性体粒子の磁気損失を利用した不要輻射低減特性に優れたものであるという点に加えて、電気絶縁性にも優れるものであり、高周波化に対応した電磁波抑制体シートである。
【図面の簡単な説明】
【図1】 電磁波抑制体シートを半導体装置全面に装着した状態を示す断面図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetic wave suppressor sheet having sufficient electrical insulation and an electromagnetic wave suppressing function.
[0002]
[Prior art]
In general, the problem of electromagnetic compatibility (EMC) has become apparent in electrical equipment, and countermeasures are taken from both aspects of emission and resistance of unnecessary electromagnetic waves. In recent years, information communication equipment has become smaller and more functional, and the operating frequency of semiconductor elements has been increasing further for higher performance. In particular, with the increase in the speed of digital signals, the signal amplitude has been reduced to reduce power consumption. The value has decreased, and there is an increased risk of malfunction even with weak high-frequency noise.
[0003]
For this reason, conventionally, as one of the countermeasures, a semiconductor package has been covered with a metal cap or a filter is mounted on a printed circuit board, but an extra mounting space is required. For this reason, the mounting density of electronic components is not sufficiently increased, and other solutions are being studied. At present, there is a demand for an electromagnetic shielding technique suitable for high-density mounting from such a background. For example, as proposed in Japanese Patent Application Laid-Open No. 9-35927 (hereinafter referred to as “prior art”), As one method of shielding by absorbing unwanted electromagnetic waves from equipment, soft magnetic particles with a large μ ″ (hereinafter referred to as “imaginary part permeability”) of complex permeability are dispersed in synthetic resin. It is known to install an electromagnetic wave suppression body sheet in the vicinity of an unnecessary electromagnetic wave generation location of an electronic device.
[0004]
[Problems to be solved by the invention]
Some conventionally used magnetic particles dispersed and blended in the electromagnetic wave suppressing sheet have a small insulation resistance value. However, an electromagnetic wave suppressor sheet manufactured by using a material in which magnetic particles having a small insulation resistance value are filled and dispersed and blended is directly installed on a lead pin of a semiconductor package, or a printed circuit board When installed on the conductor, there was a risk of short circuit. Or even if it does not lead to a short circuit, since the electrical insulation resistance value of the electromagnetic wave suppression sheet becomes small, there is also a risk of so-called signal crosstalk in which an electrical signal flows into another signal line.
[0005]
For this reason, in order to ensure electrical insulation, in the prior art, a soft magnetic material is used by using an oxidation method such as a gas phase slow acid method or a liquid phase slow acid method on the soft magnetic particles used. A technique for making non-conductivity by forming an oxide film on the particle surface is disclosed. However, the surface resistance value of the electromagnetic wave suppressor sheet obtained by the conventional technique is 10 7 to 10 8 Ω, and the electromagnetic wave suppressor sheet is installed on the lead pins of the semiconductor package even though it is effective in reducing unnecessary radiation. In this case, it has been unavoidable that it is insufficient as a countermeasure against short circuits and crosstalk.
[0006]
From the above viewpoint, magnetic particles that are highly filled in the electromagnetic wave suppressing sheet are required to have a high imaginary part permeability μ ″ and electrical insulation.
[0007]
The present invention has been made in view of such circumstances, and can suppress unnecessary radiated electromagnetic waves from electronic equipment to a high degree, and can suppress electromagnetic waves that have a high imaginary part permeability μ ″ and excellent electrical insulation. The purpose is to provide a body sheet.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the electromagnetic wave suppressor sheet of the present invention has a magnetic particle surface having a maximum particle size of 500 μm or less and an average particle size of 1 to 100 μm, and an average particle size of primary particles of 10 to 100 nm. The composite magnetic particle powder coated using mechanical impact force is formed into a sheet by a synthetic resin or rubber material dispersed in the silica fine powder. .
[0009]
That is, the present inventors, as a countermeasure against electromagnetic interference, in order to obtain an electromagnetic wave suppressor sheet excellent in unnecessary radiation reduction characteristics using the magnetic loss of the magnetic particles, the electrical insulation of the magnetic particles used as the filler A series of research was repeated. As a result, when the composite magnetic particles obtained by coating the surface of magnetic particles having a specific particle size with fine silica particles having a specific particle size using mechanical impact force are used , the volume resistivity is sufficiently high. The present inventors have found that an electromagnetic wave suppressor sheet that is high and has a significantly improved electrical insulation can be obtained, and the present invention has been achieved.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in detail.
[0011]
The electromagnetic wave suppression sheet of the present invention is formed into a sheet shape using a material made of synthetic resin or rubber obtained by dispersing and blending special composite magnetic particles.
[0012]
The synthetic resin or rubber forming the sheet is not particularly limited as long as it can be molded into a sheet shape, and conventionally known ones, for example, polyolefin resins such as polyethylene resins and chlorinated polyethylene resins, polyester resins , Polyvinyl chloride resin, silicone resin, poly (meth) acrylate resin, polyurethane resin, polyamide resin, natural rubber, isoprene rubber, butadiene rubber, acrylonitrile-butadiene rubber, carboxylated nitrile rubber, ethylene-acrylic rubber, ethylene-propylene rubber , Ethylene-propylene-diene rubber, ethylene-vinyl acetate rubber, polyether urethane rubber, acrylonitrile-butadiene-styrene rubber, styrene-butadiene rubber, acrylic rubber, fluorine rubber, fluorosilicone rubber , Thermoplastic resins such as phosphazene fluorine rubber, such as vinylidene fluoride rubber, tetrafluoroethylene-propylene rubber, tetrafluoroethylene-perfluoromethyl vinyl ether rubber, epoxy resin, phenol resin, thermosetting polyurethane resin, thermosetting Examples thereof include thermosetting resins such as unsaturated polyester resins and melamine resins, and heat-resistant resins such as polyimide resins and aromatic polyamide resins.
[0013]
The special composite magnetic particles are magnetic particles whose surfaces are coated with an insulating inorganic material.
[0014]
Examples of magnetic particles to be treated with the insulating inorganic material include hematite (Fe 2 O 3 ), magnetite (Fe 3 O 4 ), general formulas: MFe 2 O 4 , MO · nFe 2 O 3 (both formulas). Among them, M is a divalent metal particle, and examples thereof include Mn, Co, Ni, Cu, Zn, Ba, Mg, etc. n is a positive number, and M is the same kind in repetition. Various types of ferrite, silicon steel powder, permalloy (Fe-Ni alloy), Co-based amorphous alloy, Sendust (Fe-Al-Si alloy), alpalm, supermalloy, mu metal In addition, various metal powders such as permentor and permin bar, alloy powders thereof, magnetic powders and the like are used. These may be used alone or in combination of two or more.
[0015]
As the magnetic particles, particles having a maximum particle size of 500 μm or less and an average particle size in the range of 1 to 100 μm must be used. The average particle diameter is particularly preferably in the range of 10 to 50 μm. The maximum particle size and the average particle size can be measured using, for example, a laser diffraction / scattering particle size distribution analyzer.
[0016]
In the present invention, the shape of the magnetic particles to be treated is at least one selected from the group consisting of scaly (flakes), flat, dendritic, angular, granular, acicular, spongy, and spherical. Those having one shape are preferred. In particular, those having a shape with a large aspect ratio such as a scale shape (flakes) or a flat shape are suitable. In other words, the flatter the aspect ratio is, the larger the magnetic field anisotropy becomes. As a result, the magnetic loss as an electromagnetic wave suppressing body sheet obtained by dispersing and blending the surface-treated composite magnetic particles is increased. And the effect of reducing unnecessary radiation is increased.
[0017]
As the insulating inorganic material used for the surface treatment of the magnetic particles, silica fine powder is used, and spherical silica fine powder, ground silica fine powder, crushed silica fine powder and the like are particularly preferable. And the said fine silica powder whose average particle diameter of a primary particle is 10-100 nm is used from a viewpoint that a particle diameter is fine.
[0018]
Special composite magnetic particles above the surface of a coated magnetic particles treated with silica fine powder, one can be prepared as technique. That is, a processing method in which magnetic particles and fine silica powder are put into a surface treatment apparatus having a rotor, a stator, and a circulation circuit that rotate at high speed, and mechanical action using mechanical impact force such as compression, friction, shearing, etc. is repeatedly received. The above-mentioned special composite magnetic particles can be produced by using a conventionally known composite method. By such treatment, the surface of the magnetic particles is coated with silica fine powder, and composite magnetic particles in a state where the surface is coated with so-called silica fine powder are obtained.
[0019]
As described above, in the electromagnetic wave suppressor sheet obtained by dispersing and blending the composite magnetic particles obtained by using the magnetic particles having a large imaginary part permeability μ ″ and also having electric insulation, the special composite The content of the magnetized magnetic particles is preferably set to be 30 to 95% by weight, more preferably 50 to 90% by weight, and particularly preferably 70 to 85% by weight in the entire electromagnetic wave suppressing sheet forming material. In other words, if the content of the special composite magnetic particles exceeds 95% by weight, it will be difficult to produce a sheet described later, and defects such as voids will easily occur. This is because the effect of magnetic loss as a body sheet tends to be insufficient.
[0020]
Further, the special composite magnetic particles may be surface-treated with various known coupling agents in order to improve the wettability with the synthetic resin or rubber as the main component.
[0021]
The coupling agent is not particularly limited as long as it can treat the fine silica powder present on the surface of the magnetic particles. For example, γ-glycidoxypropyltrimethoxysilane, β- ( Examples include silane coupling agents such as 3,4-epoxycyclohexyl) ethyltrimethoxysilane, titanate coupling agents, aluminum chelate coupling agents, and the like.
[0022]
In addition to the synthetic resin or rubber and the special composite magnetic particles, other additives may be appropriately blended in the material for forming the electromagnetic wave suppressing sheet of the present invention.
[0023]
Examples of the additive include a thermally conductive inorganic filler, a stress reducing agent, a colorant, a coupling agent, and a flame retardant.
[0024]
Examples of the thermally conductive inorganic filler include alumina powder, aluminum nitride powder, silicon nitride powder, boron nitride powder, and kovar powder.
[0025]
Examples of the stress reducing agent include silicone compounds such as side chain ethylene glycol type dimethylsiloxane, acrylonitrile-butadiene rubber, and the like.
[0026]
Examples of the colorant include pigments such as carbon black and titanium oxide, and various dyes. Examples of the release agent include polyethylene wax, carnauba wax, fatty acid salt and the like.
[0027]
The coupling agent is the same as described above, for example, silane coupling agents such as γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, etc. Can be given.
[0028]
Examples of the flame retardant include brominated flame retardant, phosphorus-containing flame retardant, aluminum hydroxide, magnesium hydroxide and the like.
[0029]
Further, in addition to the flame retardant, a polyhedral complex metal hydroxide represented by the following general formula (1) can be used. This composite metal hydroxide has a polyhedral shape, and has a conventional hexagonal plate shape, or a so-called thin plate-like crystal shape such as a scale shape. Instead, the crystal growth in the thickness direction (c-axis direction) is large as well as length and width. For example, a plate-like crystal grows in the thickness direction (c-axis direction) and approximates more three-dimensionally and spherically. It refers to a metal hydroxide having a granular crystal shape, such as a substantially dodecahedron, a substantially octahedron, or a substantially tetrahedron.
[0030]
[Chemical 1]
Figure 0003865601
[0031]
Such a metal hydroxide having a polyhedral shape has a crystal growth in the thickness direction (c-axis direction) as well as in the vertical and horizontal directions, for example, by controlling various conditions in the production process of the metal hydroxide. A metal hydroxide having a large desired polyhedral shape, for example, a substantially dodecahedron, a substantially octahedron, a substantially tetrahedron, or the like can be obtained, and is usually composed of a mixture thereof.
[0032]
As specific representative examples of the metal hydroxide having the polyhedral shape, Mg 1-X Ni X (OH) 2 [0.01 <X <0.5], Mg 1-X Zn X (OH) 2 [0.01 <X <0.5] and the like. Examples of commercial products of these metal hydroxides include Echo Mug manufactured by Tateho Chemical Industry Co., Ltd.
[0033]
Moreover, the aspect-ratio of the metal hydroxide which has the said polyhedral shape is 1-8 normally, Preferably it is 1-7, Most preferably, it is 1-4. The aspect ratio here is represented by the ratio between the major axis and the minor axis of the metal hydroxide. That is, when the aspect ratio exceeds 8, the effect of reducing the viscosity when the epoxy resin composition containing the metal hydroxide is melted becomes poor.
[0034]
The electromagnetic wave suppressing sheet of the present invention can be produced, for example, as follows. That is, a predetermined amount of synthetic resin or rubber, which is an essential component, and composite magnetic particles and other additives are blended, mixed thoroughly by heat dispersion using a hot roll, an extruder, a kneader, etc., and passed through a rolling roll. Form into a sheet. Or after cooling once, it shape | molds by compression molding with a hot press molding machine etc. in a sheet form. Alternatively, a solution obtained by mixing a predetermined amount of composite magnetic particles and other additives in a synthetic resin or rubber dissolved in an organic solvent, and sufficiently stirring and mixing using a dispersing machine having a large shearing force such as a homomixer, After coating on a release substrate by a coating method, the sheet is dried to form a sheet. Thus, an electromagnetic wave suppression body sheet can be manufactured.
[0035]
The electromagnetic wave suppressor sheet thus obtained preferably has a volume resistivity of 1 × 10 10 Ω · cm or more, particularly preferably 1 × 10 10 to 1 × 10 17 Ω · cm.
[0036]
Further, the thickness of the electromagnetic wave suppressing sheet is appropriately set depending on the part to be used and the application, but is usually set to about 0.01 to 5 mm.
[0037]
The electromagnetic wave suppression body sheet obtained in this way is used by being installed so as to cover the entire surface of an electronic device such as a semiconductor device, for example. In the case of use such as installation so as to cover the entire surface of such an electronic device, it is tightly fixed using a commercially available double-sided adhesive tape (for example, No. 500 manufactured by Nitto Denko Corporation).
[0038]
Next, examples will be described together with comparative examples.
[0039]
[Example 1]
[Preparation of composite magnetic particles a]
An Mn—Zn flat soft ferrite powder having an average particle size of 12 μm and a spherical silica fine powder having a primary particle size of about 12 nm were prepared. The spherical silica fine powder is used in an amount of 10 parts with respect to 100 parts by weight of the Mn—Zn-based flat soft ferrite powder (hereinafter referred to as “parts”), and has a rotor, a stator, and a circulation circuit that rotate at high speed. The composite magnetic particles obtained by charging the surface of the Mn-Zn flat soft ferrite powder with the above-mentioned spherical silica fine powder after being put into a surface treatment apparatus and operated at a rotational speed of 4800 rpm for 3 minutes and then discharged from this apparatus. a was produced.
[0040]
[Preparation of electromagnetic wave suppression sheet A]
Next, 80 parts of the above composite magnetic particles a, 20 parts of a silicone rubber having a Mooney viscosity (100 ° C.) 29 before vulcanization and an ethylene-propylene-diene monomer copolymer rubber (EPDM) composite resin, γ-glycidoxypropyltri After 0.8 parts of methoxysilane was weighed and blended, 0.3 parts of dicumyl peroxide was added and kneaded and dispersed using a hot two-roll, and then passed through a rolling roll. Then, the target electromagnetic wave suppression body sheet | seat A was produced by vulcanizing at 150 degreeC for 2 hours.
[0041]
[Example 2]
[Preparation of composite magnetic particles b]
A Ni—Cu—Zn granular soft ferrite powder having an average particle size of 23 μm and a spherical silica fine powder having a primary particle size of about 100 nm were prepared. Then, the spherical silica fine powder is used in an amount of 10 parts with respect to 100 parts of the Ni-Cu-Zn granular soft ferrite powder. After operating at 2600 rpm for 10 minutes, the composite magnetic particle b formed by insulatingly coating the surface of the Ni—Cu—Zn-based flat soft ferrite powder with the above spherical silica fine powder was discharged from this apparatus.
[0042]
[Preparation of electromagnetic wave suppression body sheet B]
The composite magnetic particle b was used. Other than that was carried out similarly to Example 1, and produced the target electromagnetic wave suppression body sheet | seat B. FIG.
[0043]
[Example 3]
[Electromagnetic wave suppressor sheet C]
150 parts of the EPDM composite resin used in Example 1 was used. Other than that was carried out similarly to Example 1, and produced the target electromagnetic wave suppression body sheet | seat C. FIG.
[0044]
[Example 4]
[Electromagnetic wave suppressor sheet D]
10 parts of the EPDM composite resin used in Example 1 was used. Other than that was carried out similarly to Example 1, and produced the target electromagnetic wave suppression body sheet | seat D. FIG.
[0045]
[Comparative example]
[Preparation of magnetic particles e]
Mn—Zn flat soft ferrite powder having an average particle diameter of 12 μm was used as it was.
[0046]
[Preparation of electromagnetic wave suppression sheet E]
Next, 73 parts of the magnetic particles e and 0.73 part of γ-glycidoxypropyltrimethoxysilane were used. Other than that was carried out similarly to Example 1, and produced the target electromagnetic wave suppression sheet E.
[0047]
Using each electromagnetic wave suppression body sheet thus obtained, the imaginary part permeability μ ″, volume resistivity and noise radiation level were measured and evaluated according to the following methods. The results are shown in Tables 1 and 2 below. Also shown.
[0048]
[Imaginary part permeability μ ″]
Using each electromagnetic wave suppressing sheet, a cylindrical donut-shaped molded product (coaxial tube test molded product) having an outer diameter of 7 mm, an inner diameter of 3 mm, and a thickness of 2 mm was produced. The obtained test piece (molded product) was measured for complex permeability μ ″ at a frequency of 900 MHz by a network analyzer using a material constant measuring apparatus.
[0049]
[Volume resistivity]
Using each electromagnetic wave suppressing sheet, a disk-shaped molded body having a thickness of 3 mm and a diameter of 50 mm was produced. Then, a silver electrode having a main electrode diameter of 30 mm, a guard electrode diameter of 32 mm, and a counter electrode diameter of 45 mm was prepared using silver paste, and then volume resistivity was measured by applying DC 500V (according to JIS K 6911). ).
[0050]
[Noise emission level using semiconductor devices]
As shown in FIG. 1, a semiconductor element 1 (CMOS: 1.23 × 1.18 mm, semiconductor) is formed by a sealing resin layer 2 made of a silica powder-containing epoxy resin-based sealing material (manufactured by Nitto Denko Corporation, MP-10). The element 1 and the lead frame 3 are electrically connected by a gold wire 4), and each electromagnetic wave suppressor is disposed on the entire surface including the lead pin 5 of an SOP (small out-line package) package which is a semiconductor device sealed. The sheet (thickness 1 mm) 6 was closely attached using a double-sided adhesive tape (Nitto Denko Corporation, No. 500). While operating this resin-encapsulated semiconductor package at 20 MHz, the noise (200 to 300 MHz) radiated from the package was measured while scanning the upper 6 mm of the package with an electromagnetic wave probe at a pitch of 5 mm. .
[0051]
[Table 1]
Figure 0003865601
[0052]
[Table 2]
Figure 0003865601
[0053]
From the results of Tables 1 and 2 above, the value of the imaginary part permeability μ ″ and the noise radiation level in the SOP semiconductor package with respect to the electromagnetic wave suppression characteristics of the example products are not much different from the examples and comparative examples, and are at the same level. However, it can be seen that the example product has a large volume resistivity and is excellent in electric insulation resistance, and thus the example product clearly has an improvement effect on electric insulation.
[0054]
【The invention's effect】
As described above, the electromagnetic wave suppressing sheet of the present invention is a silica having a maximum particle size of 500 μm or less and an average particle size of 1 to 100 μm on the surface of the magnetic particles, wherein the primary particles have an average particle size of 10 to 100 nm. It is formed using a material made of synthetic resin or rubber in which powder of composite magnetic particles coated with mechanical impact force is dispersed with fine powder. For this reason, the sheet is excellent in electrical insulation, and when mounted over the leads of the semiconductor package, the sheet can efficiently reduce unnecessary radiation without causing problems such as short circuit between the leads or crosstalk. In addition, when mounting on an electronic device, it is common to form a pressure-sensitive adhesive layer such as a double-sided adhesive tape on the back surface of the electromagnetic wave suppressing sheet, and then mounting the electronic device, but the sheet should be detached. Sometimes the sheet needs to be an insulator with a high insulation resistance. Conventional sheets (for example, iron-silicon-based flat magnetic particles / rubber composite sheets) have a surface resistance of about 10 6 Ω and do not have sufficient insulation. However, since the electromagnetic wave suppressor sheet of the present invention uses composite magnetic particles whose surface is coated with silica fine powder having the above specific particle size, the insulation resistance is sufficiently high, and in the unlikely event that the electronic device is detached. Does not cause defects.
[0055]
For this reason, the electromagnetic wave suppressing sheet of the present invention has excellent electrical insulation properties in addition to being excellent in unnecessary radiation reduction characteristics utilizing magnetic loss of magnetic particles, It is an electromagnetic wave suppression body sheet corresponding to high frequency.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a state in which an electromagnetic wave suppressing body sheet is mounted on the entire surface of a semiconductor device.

Claims (2)

最大粒径が500μm以下で、平均粒子径が1〜100μmの範囲の磁性粒子表面が、一次粒子の平均粒子径が10〜100nmであるシリカ微粉末によって、機械的衝撃力を利用して被覆処理された複合化磁性粒子の粉体が分散されている合成樹脂またはゴムからなる材料によってシート状に形成されてなることを特徴とする電磁波抑制体シート。The surface of magnetic particles having a maximum particle size of 500 μm or less and an average particle size in the range of 1 to 100 μm is coated with fine silica powder having an average primary particle size of 10 to 100 nm using mechanical impact force. An electromagnetic wave suppressor sheet, which is formed into a sheet shape from a material made of synthetic resin or rubber in which powders of composite magnetic particles are dispersed. 上記複合化磁性粒子の粉体が、鱗片状、偏平状、樹枝状、角状、粒状、針状、海綿状および球状からなる群から選ばれた少なくとも一つの形状を有する粉体である請求項1記載の電磁波抑制体シート。  The powder of the composite magnetic particle is a powder having at least one shape selected from the group consisting of scaly, flat, dendritic, angular, granular, acicular, spongy, and spherical. The electromagnetic wave suppression body sheet | seat of 1 description.
JP2001177510A 2001-06-12 2001-06-12 Electromagnetic wave suppression sheet Expired - Lifetime JP3865601B2 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP2001177510A JP3865601B2 (en) 2001-06-12 2001-06-12 Electromagnetic wave suppression sheet
US10/166,024 US6695985B2 (en) 2001-06-12 2002-06-11 Electromagnetic wave suppressor sheet
EP02013406.0A EP1267406B1 (en) 2001-06-12 2002-06-12 Electromagnetic wave suppressor sheet

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2001177510A JP3865601B2 (en) 2001-06-12 2001-06-12 Electromagnetic wave suppression sheet

Publications (2)

Publication Number Publication Date
JP2002368480A JP2002368480A (en) 2002-12-20
JP3865601B2 true JP3865601B2 (en) 2007-01-10

Family

ID=19018344

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2001177510A Expired - Lifetime JP3865601B2 (en) 2001-06-12 2001-06-12 Electromagnetic wave suppression sheet

Country Status (3)

Country Link
US (1) US6695985B2 (en)
EP (1) EP1267406B1 (en)
JP (1) JP3865601B2 (en)

Families Citing this family (58)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3645197B2 (en) * 2001-06-12 2005-05-11 日東電工株式会社 Semiconductor device and epoxy resin composition for semiconductor encapsulation used therefor
DE10151036A1 (en) * 2001-10-16 2003-05-08 Siemens Ag Isolator for an organic electronic component
JP2003347787A (en) * 2002-05-23 2003-12-05 Shin Etsu Chem Co Ltd Electromagnetic wave absorbing composition
CN1292632C (en) * 2002-08-19 2006-12-27 住友电气工业株式会社 Electromagnetic wave absorber
JP4106285B2 (en) * 2003-02-12 2008-06-25 アルプス電気株式会社 High frequency equipment
US7261834B2 (en) * 2003-05-20 2007-08-28 The Board Of Regents Of The University And Community College System Of Nevada On Behalf Of The University Of Nevada, Reno Tunable magneto-rheological elastomers and processes for their manufacture
US7646095B2 (en) * 2003-09-30 2010-01-12 Panasonic Corporation Semiconductor device
US9105382B2 (en) * 2003-11-14 2015-08-11 Tundra Composites, LLC Magnetic composite
US20100280164A1 (en) 2009-04-29 2010-11-04 Tundra Composites, LLC. Inorganic Composite
JP2005154676A (en) * 2003-11-28 2005-06-16 Uchiyama Mfg Corp Magnetic rubber composition
JP4423462B2 (en) * 2003-12-22 2010-03-03 富士電機システムズ株式会社 Semiconductor power module
US7371471B2 (en) * 2004-03-08 2008-05-13 Nec Tokin Corporation Electromagnetic noise suppressing thin film
KR101007900B1 (en) * 2005-03-23 2011-01-14 후지쯔 세미컨덕터 가부시키가이샤 Semiconductor device and method for manufacturing same
JP4492454B2 (en) * 2005-06-20 2010-06-30 富士電機システムズ株式会社 Power semiconductor module
JP4853618B2 (en) * 2005-11-09 2012-01-11 戸田工業株式会社 Spherical composite particle powder for radio wave absorber, production method thereof, and resin composition for semiconductor encapsulation containing the composite particle powder
KR20080023996A (en) * 2006-09-12 2008-03-17 주식회사 하이닉스반도체 Semiconductor package
US7758784B2 (en) * 2006-09-14 2010-07-20 Iap Research, Inc. Method of producing uniform blends of nano and micron powders
JP5165231B2 (en) * 2006-11-29 2013-03-21 旭化成イーマテリアルズ株式会社 Magnetic powder-containing resin composition
JP5360947B2 (en) * 2006-12-12 2013-12-04 旭化成イーマテリアルズ株式会社 Resin composition
WO2008133172A1 (en) * 2007-04-17 2008-11-06 Hitachi High-Technologies Corporation Composite fillers for resins
DE102007025053B4 (en) * 2007-04-20 2020-09-03 Barlog Plastics Gmbh Process for producing a permanently magnetic molded part and a permanent magnetic molded part
US7815820B2 (en) * 2007-10-18 2010-10-19 General Electric Company Electromagnetic interference shielding polymer composites and methods of manufacture
US8009442B2 (en) * 2007-12-28 2011-08-30 Intel Corporation Directing the flow of underfill materials using magnetic particles
WO2009091987A2 (en) 2008-01-18 2009-07-23 Wild River Consulting Group, Llc Melt molding polymer composite and method of making and using the same
US8350367B2 (en) * 2008-02-05 2013-01-08 Advanced Semiconductor Engineering, Inc. Semiconductor device packages with electromagnetic interference shielding
US8022511B2 (en) 2008-02-05 2011-09-20 Advanced Semiconductor Engineering, Inc. Semiconductor device packages with electromagnetic interference shielding
US8212339B2 (en) * 2008-02-05 2012-07-03 Advanced Semiconductor Engineering, Inc. Semiconductor device packages with electromagnetic interference shielding
US7989928B2 (en) 2008-02-05 2011-08-02 Advanced Semiconductor Engineering Inc. Semiconductor device packages with electromagnetic interference shielding
JP5574395B2 (en) * 2008-04-04 2014-08-20 国立大学法人東北大学 Composite material and manufacturing method thereof
US7704438B2 (en) 2008-04-25 2010-04-27 Barlog Plastics Gmbh Process for producing a permanently magnetic molding
KR20110015693A (en) * 2008-07-10 2011-02-16 알프스 덴키 가부시키가이샤 Heat-conductive noise suppression sheet
US8410584B2 (en) * 2008-08-08 2013-04-02 Advanced Semiconductor Engineering, Inc. Semiconductor device packages with electromagnetic interference shielding
US20100110656A1 (en) 2008-10-31 2010-05-06 Advanced Semiconductor Engineering, Inc. Chip package and manufacturing method thereof
US8110902B2 (en) * 2009-02-19 2012-02-07 Advanced Semiconductor Engineering, Inc. Chip package and manufacturing method thereof
US8152145B2 (en) * 2009-04-29 2012-04-10 Honeywell International Inc. Isoelastic magneto-rheological elastomer isolator
US8212340B2 (en) 2009-07-13 2012-07-03 Advanced Semiconductor Engineering, Inc. Chip package and manufacturing method thereof
US8378466B2 (en) * 2009-11-19 2013-02-19 Advanced Semiconductor Engineering, Inc. Wafer-level semiconductor device packages with electromagnetic interference shielding
US8368185B2 (en) * 2009-11-19 2013-02-05 Advanced Semiconductor Engineering, Inc. Semiconductor device packages with electromagnetic interference shielding
US8030750B2 (en) * 2009-11-19 2011-10-04 Advanced Semiconductor Engineering, Inc. Semiconductor device packages with electromagnetic interference shielding
TWI497679B (en) * 2009-11-27 2015-08-21 Advanced Semiconductor Eng Semiconductor package and manufacturing method thereof
US8569894B2 (en) 2010-01-13 2013-10-29 Advanced Semiconductor Engineering, Inc. Semiconductor package with single sided substrate design and manufacturing methods thereof
TWI411075B (en) 2010-03-22 2013-10-01 Advanced Semiconductor Eng Semiconductor package and manufacturing method thereof
FR2962050B1 (en) * 2010-07-01 2015-01-30 Air Liquide METHOD FOR OPERATING A MIXED IONIC CONDUCTIVE CERAMIC MEMBRANE
TWI540698B (en) 2010-08-02 2016-07-01 日月光半導體製造股份有限公司 Semiconductor package and manufacturing method thereof
US9545043B1 (en) * 2010-09-28 2017-01-10 Rockwell Collins, Inc. Shielding encapsulation for electrical circuitry
US9406658B2 (en) 2010-12-17 2016-08-02 Advanced Semiconductor Engineering, Inc. Embedded component device and manufacturing methods thereof
WO2013022068A1 (en) * 2011-08-10 2013-02-14 日立化成工業株式会社 Photosensitive resin composition, photosensitive film, permanent resist and method for producing permanent resist
US8704341B2 (en) 2012-05-15 2014-04-22 Advanced Semiconductor Engineering, Inc. Semiconductor packages with thermal dissipation structures and EMI shielding
US8653634B2 (en) 2012-06-11 2014-02-18 Advanced Semiconductor Engineering, Inc. EMI-shielded semiconductor devices and methods of making
US9999158B2 (en) 2013-01-03 2018-06-12 Henkel IP & Holding GmbH Thermally conductive EMI suppression compositions
US9126124B2 (en) * 2013-03-15 2015-09-08 Giancarlo A. Carleo Multidirectional sensory array
US9409101B1 (en) 2013-03-15 2016-08-09 Giancarlo A. Carleo Multi-sensory module array
JP5512869B2 (en) * 2013-09-09 2014-06-04 株式会社栗本鐵工所 Radio wave absorber particles and radio wave absorbers
WO2017138158A1 (en) * 2016-02-10 2017-08-17 株式会社トーキン Composite magnetic material and method for manufacturing same
KR102620863B1 (en) * 2016-08-19 2024-01-05 에스케이하이닉스 주식회사 Semiconductor package having electromagnetic interference shielding layer and method of fabricating the same
CN108976804A (en) * 2018-08-15 2018-12-11 合肥卓汇新材料科技有限公司 A kind of reinforced filling improving Mechanical Properties of Silicone Rubber
JP2020150036A (en) * 2019-03-11 2020-09-17 藤倉化成株式会社 Magnetic paint composition
KR20210010175A (en) * 2019-07-19 2021-01-27 현대자동차주식회사 Magneto-Rheological Elastomer

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0614485B2 (en) * 1988-05-25 1994-02-23 大八化学工業株式会社 Surface-modified magnetic powder and bonded magnet composition containing the same
JPH0278299A (en) * 1988-09-14 1990-03-19 Hitachi Ltd Electronic component mounting board
FI117224B (en) * 1994-01-20 2006-07-31 Nec Tokin Corp Electromagnetic interference suppression piece, applied by electronic device and hybrid integrated circuit element
JPH0935927A (en) * 1995-07-20 1997-02-07 Tokin Corp Composite magnetic body and electromagnetic interference suppressor using the same
JP3475386B2 (en) * 1997-09-01 2003-12-08 Necトーキン株式会社 Electromagnetic interference suppressor
JP3555831B2 (en) * 1998-01-20 2004-08-18 株式会社ルネサステクノロジ Semiconductor device and electronic device
JPH11269503A (en) * 1998-03-19 1999-10-05 Hitachi Metals Ltd Iron-base nano-crystal magnetic powder, its production, and radio wave noise inhibiting member using the same
JP2000114440A (en) * 1998-10-07 2000-04-21 Daido Steel Co Ltd Heat radiating sheet
JP2000228598A (en) * 1999-02-08 2000-08-15 Daido Steel Co Ltd Electromagnetic wave absorber having high dimensional stability
JP2000269680A (en) * 1999-03-17 2000-09-29 Nippon Paint Co Ltd Electromagnetic wave absorbing board
JP2000294977A (en) * 1999-04-05 2000-10-20 Nitto Denko Corp Electromagnetic interference repressor and production thereof
JP2001060792A (en) * 1999-08-19 2001-03-06 Sony Corp Electromagnetic wave absorber
DE60011199T2 (en) * 1999-10-06 2004-09-30 Nitto Denko Corp., Ibaraki Resin composition for the encapsulation of semiconductors, semiconductor devices containing them and methods for the production of these semiconductor devices
JP3629390B2 (en) * 1999-11-25 2005-03-16 日立粉末冶金株式会社 High frequency powder magnetic core and method for manufacturing the same
JP3925835B2 (en) * 2000-04-10 2007-06-06 株式会社日立製作所 Electromagnetic wave absorber, its production method and various uses using it
KR100533097B1 (en) * 2000-04-27 2005-12-02 티디케이가부시기가이샤 Composite Magnetic Material and Magnetic Molding Material, Magnetic Powder Compression Molding Material, and Magnetic Paint using the Composite Magnetic Material, Composite Dielectric Material and Molding Material, Powder Compression Molding Material, Paint, Prepreg, and Substrate using the Composite Dielectric Material, and Electronic Part
JP3645197B2 (en) * 2001-06-12 2005-05-11 日東電工株式会社 Semiconductor device and epoxy resin composition for semiconductor encapsulation used therefor

Also Published As

Publication number Publication date
EP1267406A3 (en) 2005-01-19
EP1267406B1 (en) 2017-02-08
JP2002368480A (en) 2002-12-20
US20020198286A1 (en) 2002-12-26
EP1267406A2 (en) 2002-12-18
US6695985B2 (en) 2004-02-24

Similar Documents

Publication Publication Date Title
JP3865601B2 (en) Electromagnetic wave suppression sheet
EP1266936B1 (en) Epoxy resin composition used for encapsulating semiconductor and semiconductor device using the composition
JP4849220B2 (en) Electromagnetic interference suppression sheet and manufacturing method thereof, flat cable for high-frequency signal, and flexible printed circuit board
JP4764220B2 (en) Thermally conductive sheet
JP2006032929A5 (en)
JP2006032929A (en) Electromagnetic interference inhibitor, method of reducing electromagnetic interference empolying it, and rf-id device
US20110203835A1 (en) Conductive magnetic filler, resin composition containing the filler, electromagnetic interference suppressing sheet using the resin composition and applications thereof, and process for producing the electromagnetic interference suppressing sheet
US11322425B2 (en) Semiconductor device
JP2008021990A (en) Electromagnetic interference suppressor and method of suppressing electromagnetic fault
JP2006269892A (en) Electromagnetic wave shielding molded article
EP2723154A1 (en) Electromagnetic wave interference suppressor
KR101560570B1 (en) Composition for complex sheet with EMI shielding and absorbing, thermal dissipation and electric insulation, and complex sheet comprising the same
CN104854974A (en) Electromagnetic interference suppression body
TW200908871A (en) Sheet for prevention of electromagnetic wave interference, flat cable for high-frequency signal, flexible print substrate, and method for production of sheet for prevention of electromagnetic wave interference
JP2009278137A (en) Electromagnetic wave absorbing material
JP5103780B2 (en) Electromagnetic interference suppression sheet, high-frequency signal flat cable, flexible printed circuit board
JP2008001757A (en) Resin composition for semiconductor sealing use and resin-sealed type semiconductor device
JP4859028B2 (en) Electromagnetic wave prevention sheet, electromagnetic wave prevention sheet manufacturing method, and electromagnetic wave prevention structure of electronic component
JPH1074611A (en) Composite magnetic substance, its manufacture, and electromagnetic interference suppresser
JP3668403B2 (en) Epoxy resin composition for semiconductor encapsulation and semiconductor device using the same
KR20110064444A (en) Electromagnetic wave absorber with anti-flammability and non-halogen using flaky soft-magnetic filler in low frequency range, and manufacturing method
JP2003273568A (en) Capsule type electromagnetic wave absorption material
JP2005286191A (en) Laminated electromagnetic wave absorber
JP2005510070A (en) Electromagnetic wave reducing material and reduction method
JP2005510070A6 (en) Electromagnetic wave reducing material and reduction method

Legal Events

Date Code Title Description
A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20051222

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20060110

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20060313

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20060516

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20060718

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20060919

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20061003

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

Ref document number: 3865601

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20101013

Year of fee payment: 4

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20101013

Year of fee payment: 4

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20111013

Year of fee payment: 5

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20111013

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20141013

Year of fee payment: 8

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

S531 Written request for registration of change of domicile

Free format text: JAPANESE INTERMEDIATE CODE: R313531

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

S111 Request for change of ownership or part of ownership

Free format text: JAPANESE INTERMEDIATE CODE: R313117

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

EXPY Cancellation because of completion of term